1. Technical Field
The invention relates to a hydraulic shock absorber with two-way action, with a pressure tube, completely or partially filled with hydraulic oil, in a housing, and with several throttle openings with fixed or variable settings, which are distributed over the length of the pressure tube and are connected on one hand to a pressure space of the pressure tube and on the other hand to cavities of the housing, with piston rod seals at the ends.
2. Background Information
Shock absorbers are utilized in many technological fields. Easily the largest number of shock absorbers are used for vehicles, where shock absorbers with one-way and with two-way action are both used. The purpose of these shock absorbers is to keep the vehicle as free as possible from vibrations during travel.
In addition to this, shock absorbers are already known on machines and equipment, and have the purpose of braking moving masses over a predetermined path and as free as possible from vibrations. Handling equipment, industrial robots and the like belong to this category.
Since very large takup power has to be accommodated in the minimum space, these shock absorbers are divided into a high pressure part in front of the piston and a lower pressure region outside the pressure tube. The whole piston surface can thereby be usefully used, the seals being easily accessible and pressure-relieved. Of course, these shock absorbers are not suitable for two-way action, so that in order to brake moving masses in both directions practically twice the constructional expenditure must be undertaken, which is often not available in manipulating devices such as handling equipment and industrial robots.
The following listed German, British and U.S. patents were known by the applicant when this application was filed.
DE-OS No. 2,937,242 PA0 DE-OS No. 2,932,553 PA0 DE-OS No. 2,925,948 PA0 DE-OS No. 2,918,644 PA0 DE-PS No. 3,224,088 PA0 DE-PS No. 3,217,864 PA0 DE-PS No. 2,803,514 PA0 DE-PS No. 2,322,816 PA0 DE-PS No. 2,105,422 PA0 DE-PS No. 1,256,485 PA0 DE-GM No. 8,234,698.4 PA0 DE-GM No. 7,924,834 PA0 DE-GM No. 7,913,388.3 PA0 German application No. 7,202,036.1 dated: Apr. 20, 1972 PA0 U.S. Pat. No. 3,168,168 PA0 British Pat. No. 1,100,089